[HTG] Repeater - Core Solar Build
Description
This build is typically used for "Core" type repeaters (see [ENT] Node Names for a breakdown of the node types). This build is aimed for 915MHz regions (specifically Australia); adjust any frequency-specific items accordingly (they will be flagged as such).
| Difficulty Rating | Moderate |
| Power Source | Solar |
| Battery Chemistry | LiFePo4 |
| Battery Capacity | 7Ah |
| LoRa TX Power | 0.15W |
| Runtime (No Charging) | 10-14 days |
Bill of Materials
Base Build
Below is the baseline list of minimum required materials to complete the build. There are optional extras if there are special requirements for the location, available in the next section.
| Item | Link | Notes |
| Enclosure | TBD. This is being re-evaluated. | |
| Dev Board | Seeed Xiao nRF52840 + Wio-SX1262 kit. | |
| Antenna (915MHz) | AliExpress | Typically the 35cm, 45cm and 55cm antennas are used for Core locations. Less is more when it comes to antenna gain with LoRa. Yes, lower gain really will (almost always) perform better. |
| N-female Pigtail | AliExpress | The RG174 cable on this is quite rigid. If you need to bend the cable to get the dev board into place, choose a longer length cable so you have room to flex without adding sharp bends. |
| JST Connectors | AliExpress (5/10 pairs) | Connectors for the solar panel, battery and dev board to the charge controller. You will need 3 pairs per node. |
| Breather/Vent Plug | AliExpress (10 pcs) | Allows airflow to the enclosure and water to drain if a leak develops. Strongly advised. Ensure you have a drill bit or hole saw for the chosen size. Typically we use the M12x1.5-10 size. |
| Battery Holder | AliExpress | Choose the 26650 2-Cell option. |
| Battery Cells | AliExpress | Get 2 cells. The manufacturer is reputable and their cells have been tested by trusted experts in the IoT space (shout out to Andreas Spiess). The listing is for cells with protection modules fitted. |
| Solar Panel | AliExpress | Allegedly 10W but likely closer to 3-5W. With decent sun you should be able to fully charge a depleted battery pack in ~1 day. |
| Solar Charge Controller | AliExpress (1/3/5 pcs) | Choose the TP5000 option. This is rated for LiFePo4 voltage and has a USB-C connector as well (Not PD capable). Note: the listing will say "3.6V", this is fine; it's the fully-charged voltage of the cell (3.2V nominal voltage). These are tested and confirmed safe. |
| Cable Gland | AliExpress (10pcs) | Allows the solar panel cable to enter the enclosure while maintaining a seal. |
Optional Extras
| Item | Use Case | Link | Notes |
| Band Pass Filter | Low-to-moderate RF interference at install location (e.g. near a cellular transmitter). | AliExpress | Ensure you choose the right version for your country (e.g. 915MHz for Australia). |
| N female to SMA female bulkhead + SMA male to u.FL pigtail | If using the band pass filter, you will need to switch the N female to u.FL pigtail connector with this instead. | Be mindful to choose the SMA version of the pigtail and not the RPSMA. Also, the cable will not have a lot of flex so choose a longer cable to allow more flex if you have tight space in the enclosure. |
Build Instructions
Coming Soon (TM)